Fighters from Germany take up position before competing in the Medieval Combat World Championship at Malbork Castle, northern Poland, April 30, 2015. Medieval combat is a full contact sport that revives the foot based tournament fighting of medieval Europe. Countries fight in refereed matches where the objective is to get the opposing team to the floor. There are also duels with polearms, swords and shields where the number of hits landed are scored. The fighters, both male and female, wear heavy armours and weapons, mostly replicas of authentic pieces, and fight following the knights code of conduct. According to organizers, 25 nations from 6 continents are taking part in the Championships, which started on April 30 and will go on until May 3. (Photo by Kacper Pempel/Reuters)

A two-horse team street cleaner, with sprayer, squeegee, and roller at rear. New York, between ca. 1910 and ca. 1915. (Photo by NYC Municipal Archives)

Women perform square dancing at a park square in Beijing, China, April 9, 2015. Chinese-style square dancing is running circles around other hobbies for the elderly, with millions taking to parks and plazas across China, swivelling their hips and rolling their arms – but it's not to everyone's liking. (Photo by Kim Kyung-Hoon/Reuters)

Students at the Cuba's National Ballet School (ENB) watch a class from outside the classroom in Havana, Cuba, October 12, 2016. Catherine Conley, the first American full-time student at Cuba's prestigious National Ballet School, hopes to gain an edge back home by learning the powerful Cuban style with its dazzling turns and jumps. (Photo by Alexandre Meneghini/Reuters)

Dressed for the traditional New Year's festival known as “La Diablada”, in Pillaro, Ecuador, Friday, January 5, 2018. Thousands of singing and dancing devils take over the mountain town for six days of revelry in the streets. Local legend holds that anyone who adopts a costume for the celebration and wears it at the event six years in a row will have good luck. (Photo by Dolores Ochoa/AP Photo)

Reverend Simon Davis prays with the dancers before the Abbots Bromley Horn Dance in Abbots Bromley, Britain, September 12, 2016. The Abbots Bromley Horn Dance is an English folk dance dating back to the Middle Ages. (Photo by Darren Staples/Reuters)

Regina Halmich and Sergiy Plyuta perform during the 'Let's Dance' TV show at Coloneum on March 23, 2011 in Cologne, Germany.